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Radio Quiet Zones (RQZ) - working with your national administration

Radio Quiet Zones (RQZ) - working with your national administration. Tasso Tzioumis Australia Telescope National Facility (ATNF) Tasso.Tzioumis@ .csiro.au COSPAR2008 – Montreal 14 July 2008. Why? -- Need for RQZ?. RA systems extremely sensitive  very susceptible to RFI

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Radio Quiet Zones (RQZ) - working with your national administration

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  1. Radio Quiet Zones (RQZ)- working with your national administration Tasso Tzioumis Australia Telescope National Facility (ATNF) Tasso.Tzioumis@ .csiro.au COSPAR2008 – Montreal 14 July 2008

  2. Why? -- Need for RQZ? • RA systems extremely sensitive  very susceptible to RFI • RA allocated very little spectrum (~2% at cm ) • Still RFI from out-of-band (OoB) emissions • RA operates over full radio spectrum  RFI from radiocommunication services • “prevention better than cure”  RQZ is 1st step of mitigation

  3. What? -- Radio Quiet? • Radio Quiet  Radio Silent • “Passive” bands (e.g. 1400-1427 MHz) • “all emissions are prohibited” (Fn. 5.340) • but OoB emissions still a problem • RQZ  prevent “harmful” (detrimental) RFI • RFI mitigation – minimise “harm”  may influence RQZ limits & area

  4. RQZ selection - Population? Sydney: population 4 million Narrabri: population 4000 Mileura: population 4

  5. Where are the Quiet areas?

  6. RQZ History • National RQZ • Within an administration • Sovereign rule – can depart from ITU • Regulate terrestrial services • Little or no impact on satellite services • International RQZ • Moon & L2 point

  7. National RQZ characteristics • 2 distinct areas of RQZ protection • EMC protection • RFI from electrical/electronic equipment • Protect to few kms (5-20) – 30 for heavy industry • Local/State Governments • Coordination zone • Coordinate with radio transmitters • 100s of km • Communications administration

  8. Greenbank NRQZ • The original RQZ - model • 1956 – West Virginia Radio Astronomy Zoning Act • Graded EMC restrictions to 10 miles • 1958 – NTIA & FCC National RQZ • 34000 sq km area • Coordination of all Tx with RA telescope • Excellent protection in practice

  9. Other National RQZs • Arecibo PRCZ – Puerto Rico & islands • Coordination Zone • Jodrell Bank & other European telescopes • Mainly EMC (local) & some National coordination • GMRT • EMC – 10 km (light)30 km (heavy industry) • National coordination up to 400 km (bands)

  10. ALMA Quiet Zone -- Chile • Central Quiet zone: 30 km radius, no transmitters in ALMA bands (variously 31 to 950 GHz) • 120 km radius coordination zone • AUI/ESO may comment on xmit applications • > 31 GHz, comply with 769 at site boundary • < 31 GHz, 769 + limit on transmitter power • Eirp such that pfd at ALMA border <2x10-6 W/m2 • Formal recognition is needed to avoid future changes in policy. • Need to educate the general public and politicians about radio astronomy and the need for radio quiet zone.

  11. “Radio sensitive zones” in Australia • Radio Act review 2002 – “radio sensitive zones” • Notification and coordination - no protection • Regulatory RALI (2006) to cover all Oz RA sites • Studies by ACMA (administration)

  12. RA. 769 thresholds

  13. Notification Zone Parameters • Limits derived from RA.769 (+ ~10-15 dB) • Propagation models from P.526 (Diffraction) and terrain models.

  14. International RQZs • Shielded Zone of the Moon RQZ • ITU-R Rec RA.479 - Entire radio spectrum • No levels defined – coordination • But some RFIfrom spacecraft (e.g. Mars) • Prohibitively expensive • Sun-Earth Lagrangian Point L2 • ITU-R Rec RA.1417 • 1.5 million km from Earth • Excellent RQZ – WMAP (CMB) already there!

  15. OECD Global Science Forum • OECD “Task Force on Radio Astronomy and the Radio Spectrum” (Report 2004) • RA and Satellite Operators • Recommendations: • Technical consultations • “Controlled Emission Zones” • ITU-R efforts • Operational consultation • Leverage for international RQZ?

  16. ITU-R Question • Question in WP7D to initiate studies • Strong opposition from satellite operators • Question delicately framed i.e. • Characteristics of existing RQZ? • RAS characteristics stimulating RQZ? • environment characteristics stimulating RQZ? • Work still to be done.

  17. Square Kilometre Array (SKA) • ~ 1 km2 collecting area in an interferometer array • sensitivity ~50 x EVLA (current largest radio array) • survey speed >10000 x faster than EVLA • wide frequency range: 0.1 – 25 GHz • configuration: longest baselines >3000 km; • 50% collecting area<5km • wide field of view: 50 sq. degree at <1 GHz(250 x moon) • total cost 1 B€; operating costs 70 M€/year

  18. SKA Reference Design Inner core Station Wide-angle radio camera + radio “fish-eye lens”

  19. RQZ for SKA? • SKA to operate 100 MHz – 25 GHz • Wide unprotected frequency range • Must have some RQZ protection • National efforts towards SKA RQZ(s) • All site proponents must define progress towards RQZ protection. • Short list: Australia & South Africa • Protection now for SKA demonstrators / pathfinders • Preserve “quiteness” of sites • e.g. Australia started with a “spectrum embargo” for 100-150 km radius around Mileura site.

  20. RQZ guidelines -SKA Regulatory “Task Force” • Report covers Protection criteria and general discussion on methodology. • Threshold levels: • “Central site” - RA.769 levels (cont & line) • Up to 150km - RA.769 Table 1 +15dB (array levels) • Remote sites - RA.769 VLBI levels • Radio propagation modelling (ITU Recs) • Complex and many assumptions

  21. South Africa Astronomy Reserve

  22. South Africa Legislation: Astronomy Geographical Advantage Act • Empowers the Minister for Science and Technology to declare protected areas around strategic astronomy sites by publication in the Government Gazette. • The Act empowers the Minister to prohibit over-flights • The Act covers both radio and optical astronomy • Three tiers of protected areas: • Core area – the physical area of the observatory / instrument • Central area – surrounds the core area. Minister prohibits certain activities / categories of activities in this area • Coordination area –Minister sets standards which activities must comply with • Protected areas apply to existing and new activities

  23. ASKA - Australia + NZ

  24. SKA RQZ in Australia • Studies & definition by ACMA & CSIRO • RALI MS32 - in force since 24/9/2007

  25. Oz RQZ procedures • From RALI MS32

  26. Oz RQZ – EMC - 1 • EMC – RFI from unintentional transmitters • Industrial & domestic machinery • Oz - RFI from Mining activities • Mining equipment • Communications used by mines (e.g. VHF & UHF radio) • Infrastructure for ore transport (Rail & trucks) • Need limits and exclusion zones • Limits as per RQZ •  Mineral Resource Management Area ** Work with Regional authorities **

  27. Oz RQZ – EMC - 2 • Other RQZ RFI issues • RFI from co-located science instruments (MWA) • Self-generated RFI • Buildings; Computers; Telescope electronics • Must develop EMC Limits & Testing protocols • Base on MIL standards for testing • But very difficult to test to RA.769 levels • Correlation spectrometers • Radio telescope testing (e.g. at Parkes) • Must manage and mitigate self-RFI

  28. Summary & lessons learned • RQZs important for RA – 1st step in mitigation • National “RQZ”s - coordination only • Weak enforcement • RQZ essential for SKA • Exclusion and coordination zones • Strong Enforcement • EMC controls and testing also critical • Lesson from Oz experience: ** Work closely with national communications administration ** ** Work closely with Regional bodies and Governments * • ITU Question on RQZ – towards IRQZs? • Inputs from SKA RQZ experience

  29. Comment on the SKA RQZ in Australia in a speech by the chairman of the Australian Communications and Media Authority:

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